Step-ladder



(No Model.) C. L. SMITH.

STEP LADDER.

No. 443,299. Patented Dec. 23, 1890.

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PATENT FFICEQ CHARLES L. SMITH, OF PITTSBURG, PENNSYLVANIA.

STEP-LADDER.

SPECIFICATION forming part of Letters Patent No. 443,299, dated December 23, 1890.

Application filed October 4, 1890. Serial No. 367,095- (No model.)

To ail whom it may concern:

Be it known that 1, CHARLES L. SMITH, a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Step-Ladders; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to step-ladders and to what might be termed rolling step-ladders--namely, that class of ladders which are arranged to be run on a suitable track along the shelving of a store or library, in order to give access to the goods or books upon the shelves its object being to improve this class of ladders in certain particulars, such as the overcoming of the great strain upon the upper portion of the shelving by properly distributing the weight upon the shelving to prevent the ladder from jumping off the rail or track, to provide for the gripping or holding of the track by the ladder when supporting a weight, so preventing traveling of the ladder upon the track and overcoming the danger of accident from such cause, and to improve the ladder in other particulars.

To these ends my invention consists, generally stated, in combining with shelving having a track a ladder having rollers traveling on said track and below the same having rollers mounted at an angle to the top rollers and acting to support the lower part of the ladder, such construction giving the proper and more direct support to the lower part of the ladder, while at the same time the lower rollers act to divide the weight with the upper rollers, giving an upward support to the lower end of the ladder and relieving the upper rail of the great strain to which such rails have heretofore been subjected.

It also consists in mounting the upper roll ers traveling on the track on a spring in such way that when a heavy weight is thrown upon the ladder the spring will yield sufficiently to cause the cant-ing of the roller, so causing it to grip the rail and prevent the traveling of the ladder thereon.

It also consists in certain other improvements, as will be hereinafter more particularly set forth and claimed,

To enable others skilled in the art to make and use my invention,l will describe the same more fully, referring to the accompanying drawings, in which- Figure 1 is a perspective view of a set-of shelving, illustrating my invention in its application to a ladder hanging from the top of the shelving and to a ladder running on the platform of the shelving. Fig. 2 is a sectional view of the bracket traveling upon the upper rail, illustrating the method of gripping the rail when the ladder carries a heavy weight; and Fig. 3 is a cross-section of the ladder.

Like letters of reference indicate like parts in each.

The shelving a is meant to illustrate any suitable store-shelving, said shelving having the usual platform, upon which the boxes can be placed when desired, and also having above the same an extension for holding like goods, as at c. In reaching the goods above the shelving it is generally necessary to have a ladder hung from a rail near the top of the shelving, such rail being shown at (Z, and consisting simply of a long rectangular metal bar, which is held out from the shelving the desired distance by means of circular bosses d,through which bosses the screws securing the rail in place pass, said screws then passing into the body of the shelving and securing both the rail and the bosses thereto. The advantage of such construction is that a smooth and parallel upper and lower track is obtained, the one for the circular rollers to run on and the other for the guard-roller to pass under, and so prevent the rising of the ladder. The upper roller is supported in a suitable bracket, which is more clearly shown in Fig. 2, one bracket being placed on each side of the ladder. Each bracket 6 has a seat for the roller, as at f, formed by the body of the bracket, and the arm f, in which is formed abearing, as at f, the roller g fitting into said seat and being mounted upon a shaft or bolt h, which extends through said bearing f and through suitable bearings 7?. 7L2 formedin the bracket.

When it is desired to give to the roller the gripping action above referred to, I employ beside the seat f a spring-seat 7c, said seat bein g simply a vertical circular chamber to inclose a spring 2', which spring will act upon the bolt h, on which the roller is mounted with sufficient force to hold it down inits bearings when the ladder carries no weight;

but will yield when weight is thrown upon the ladder. It will be noticed that the outer bearings for the bolt 7Lthat is, the bearing f in the arm f and the bearing h nearest 5 the roller-are formed oblong or slotted, while the in nerbearin g 7L corresponds substantially in size to the bolt. The inner bearing therefore acts as a fulcrum for the shaft, while the leverage to force down the roller is applied 10 by the spring i within the seat 7., and even though a heavy spring is used, as it is near the fulcrum it can be easily compressed by the weight thrown upon theladder. The belt it generally carries a hollow ball m within I 5 the seat Z: to receive the pressure from the spring. On the bracket 6, below the roller g and extending out below the rail d, is a bolt or shaft 21, which is secured in a suitable seat in the bracket, being held in place by suitable nuts 01. n, this belt carrying a small roller 11*, which extends under the rail (Z and forms the guardroller to prevent the roller 9 from rising off the rail.

At the lower end of the ladder at each side thereof is the bracket 17, which extends out in a diagonal direction from the ladder and forms a bearing for the roller 1), the rollers being mounted therein in such diagonal position, so that said rollers can rest upon a 0 beveled or like edge of the shelving and give a partial support to the ladder. It is well known that the mass of such shelving has the outer edge of the platform 1) formed beveled,

as shown at l), and these rollers 17 are gener- 3 5 ally adjusted to travel upon such beveled edge, the upper rollers acting to take the vertical strain upon the ladder, while the lowerv rollers act to take the inward pressure, at the same time dividing to a great extent the downward strain of the weight of the person upon the ladder, and in that way relieving the top part of the shelving from any very heavy strain. Practical use of the device as so constructed has proven it exceedingly cf- 4 5 ficient for the purpose. At the same time, in case the beveled edge i) is not exactly parallel with the rail cl, it is evident that the roller 1) may roll upward or downward upon such beveled edge 1/, the inclined position of the roller permitting such action of the roller while giving upward support to the ladder. The rollers p are preferably made of rubber or are rubber-faced, so that they will not mar the beveled edge of the platform or other surface on which they travel. In the smaller ladder shown in Fig. 1 the same construction is employed, the rail (7, however, being a T-rail secured to the platform I), on which the grooved roller runs, while the rollers 17 travel on a beveled face at the base of the shelving, so holding out the lower end of the ladder. The guard-roller n can in such case extend under the edge of the platform, and so prevent the rising of the roller therefrom. It is in con- 6 5 nection with such a short ladder running on the platform that the spring-operated roller above described has the principal advantages,

as where the weight is thrown on the upper part of this ladder and above the rollers 5 thereof. In case the ladder is free to move on its roller it is evident that where the weight of the person is thrown to the one or the other side, the ladder might be liable to travel along the rail away from the person standing thereon, and so cause serious accident. here, however, the weight of the person is sufficient to compress the spring i, and so cause the roller to grip the rail, all liability of the travcling of the ladder is prevented, the weight of the person imparting to the ladder a ti rm hold upon the rail. lVhen, however, the said weight is relieved, the springs will force down the bolt 7:, so relieving the rollers g from their gripping action, and the ladder can be caused to travel along the rail with butlittle expenditure of force. This gripping-roller may of course be employed where the ladder is hung from its top and from the top of the shelving, if desired; but if it is not so desired the bearings for the bolt 7L may be made to correspond thereto, while the spring-seat 7. and the spring i may be dispensed with.

As it is extremely desirable in mounting such ladders to have some means of supporting the upper part of the person, and as it is also found necessary to employ the board sides to the ladder in order to support the steps and provide a body to which to secure the brackets in order to give the hand-rail to the ladder, I prefer to construct them in the manner illustrated more particularly in Fig. 3, which shows a cross-section of the ladderbody. In said ladder body there are the side boards 2' r, to which the steps 8 are connected, and extending along the front edge of said side board are the moldingstrips 25, these molding-strips being of greater width than the thickness of the said boards, and so forming a lip extending out beyond the body of the ladder along the front edge thereof for the entire length of the ladder, so giving the necessary hold to any person mounting on the same, so that they can keep a support themselves upon the ladder without the necessity of reaching back to the side thereof.

In the use of the ladders as abovedescribed it is found that they will travel easily along the track; made for them, while by the simple guard-roller they are prevented from rising therefrom; that in the support of the ladder the lower rollers, while holding the ladder out from the shelving, act to divide with the up per rollers the weight of the ladder and the weight of the person thereon, since they are supported in a diagonal position oraposition at an angle to the upper rollers, and consequently sustain to some extent the downward pressure upon the ladder, it being found that by such construction the ladder can be operated without as great a strain upon the upper part of the shelving. At the same time by providing means for gripping the rail when desired the movement of the ladder when supporting the weight of the personis prevented,

IIO

and a proper hand-rail to be grasped by the person upon the ladder is also provided.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In stepladders, the combination, with shelving having a track thereon, of a ladder having rollers traveling on said track and having rollers below the same mounted diagonally to the top rollers and bearing on the shelving and acting to support the lower part of the ladder, substantially as and for the purposes set forth.

2. In step-ladders, the combination of shelving having a track thereon and having a beveled face below said track, a ladder having rollers traveling on said track and having rollers below the same mounted diagonally to the top rollers and substantially parallel to the beveled face and traveling on said beveled face, substantially as and for the purposes set forth.

3. In step-ladders, the combination, with shelving having a track thereon, of a ladder having rollers traveling on said track, said rollers being mounted so as to cant when supporting a heavy weight and grip the track, substantially as and for the purposes set forth.

4. In step-ladders, the combination, with shelving having a track thereon, of a ladder having rollers traveling on said track, said rollers being mounted on canting shafts, so as to act to grip the track, substantially as and for the purposes set forth.

5. In step-ladders, the combination, with shelving having a track thereon, of a ladder having rollers traveling on said track, said rollers being mounted on oanting shafts so as to grip the track, and springs acting upon said shafts to hold them down and prevent the canting thereof, substantially as and for the purposes set forth.

6. In step-ladders, the combination, with the shelving having a track thereon, of the ladder having the brackets e, each of said brackets being provided with the shaft h, carrying the roller g, running on said track, and said shaft being mounted at one end in a bearing corresponding in size thereto and at the other end in an oblong bearing, and a spring pressing upon said shaft, substantially as and for the purposes set forth.

7. In step-ladders, the combination, with shelving having a track thereon, of theladder carrying the brackets said brackets having rollers running on said track and being pro vided with the shaft 7t, extending out below the un der face of the track and acting to hold the rollers upon the track, substantially as and for the purposes set forth.

8. In step-ladders, the ladder body formed of the side boards 1' and steps 5 and provided With the molding-strips t, secured to the front edges of the side bars and extending out beyond the same, substantially as and for the purposes set forth.

In testimony whereof I, the said CHARLES L. SMITH, have hereunto set my hand.

CHARLES L. SMITH. Witnesses:

ROBT. D. TOTTEN, J. N. 'COOKE. 

